The majority of pet owners will have received numerous vaccinations themselves over the course of their lives. For most infectious human diseases, after an initial course as babies or young children no further vaccines are required; or maybe a single booster shot every decade or so. It can be hard to understand why our pets need much more frequent vaccination. And why, when those vaccinations lapse they sometimes need to restart the whole course.
The current climate has meant that many pets have had their yearly vaccination appointments cancelled or delayed. If your pet’s vaccinations are overdue by more than around 3 months, your veterinary surgeon is likely to recommend that your dog restarts their vaccination course. This generally means that they repeat the vaccination course that they had as a puppy – two injections usually 2-4 weeks apart. It can feel like there is lots of varying advice as to whether this is really necessary. But it comes down to just a few factors.
In the UK we recommend almost all dogs receive regular vaccinations against four major canine infectious diseases. These are Canine Parvovirus (CPV), Canine distemper virus (CDV), Canine adenovirus (CAV) and Leptospirosis.
Core Canine Vaccinations: CPV, CDV and CAV are viral diseases and considered core vaccinations for all dogs around the world.
After vaccination for these three, a strong and long lasting immunity is produced in the majority of dogs. In most cases this lasts for a minimum of three years. Logically most veterinary professionals recommend booster vaccinations against these components every three years. This is actually quite a long time if you compare the relative life spans of humans and our canine friends. If your pet has gone over the three year mark for a vaccine against these three, a single booster injection should be sufficient to kick start their immunity and offer full protection.
Leptospirosis
In the UK it is recommended that Leptospirosis is also considered a core vaccination as it is relatively common. Leptospirosis is a disease caused by a group of bacteria. It is usually caught from rats, farm animals or stagnant water contaminated by animal urine. The disease causes severe liver and kidney damage and in its most severe form can be fatal. It is also important as a zoonosis. This means that it is a disease that can be contracted by humans from animals. For these reasons it is very important to keep your pet’s leptospirosis vaccinations up to date.
The problem with leptospirosis vaccines is that they do not produce the same long lived immunity as the viral infections we vaccinate against. Data shows that for most dogs the length of time they are immune following vaccination for Leptospirosis is less than 18 months and often closer to 12 months. If your pet runs over the due date for their leptospirosis vaccine by more than a few months it is necessary to give the full primary course of two vaccinations again. This is to ensure they are fully protected.
Can a dog have sufficient levels of immunity that mean they do not need to restart their vaccines?
For the viral diseases (CDV, CPV and CAV) this is a simple matter of measuring antibody levels on a blood test. There is a pretty good correlation between high antibody levels and adequate protection against disease. So we know we can allow these pets to go over their normal vaccination interval. However, this is not the case with Leptospirosis. When antibody levels drop very quickly after vaccination and are in any case not good at predicting whether your pet is protected. This is another reason why your vet will recommend restarting the course of Leptospirosis vaccines if they have lapsed for a certain period of time.
Success of dog vaccination programmes
Many of the diseases we vaccinate against have become rare. However, they have not disappeared. It is important that our dogs are kept up to date with their vaccinations. This is to give them the best possible protection against these serious illnesses. Thankfully vaccination complications are very rare. But if you have any concerns or questions about your pet’s vaccinations your veterinary surgeon will be very happy to answer them.
You might also be interested in:
- How do dog vaccines work?
- How to Talk to My Vet if I’m Worried about My Pet Having Annual Vaccinations
Discussion
Hi,
My dog is due her annual lepto vac, but every year i’m still worried that she is not fully vaccinated, due to the initial mistake the vet made when giving her second lot of puppy vacs. As a puppy, she was first given L2 at the breeder’s vet, and then once she was home with us, our vet mistakenly gave her L4. I was advised that due to this, she would still be fully vaccinated for the 2 strains in L2, but if i did wish for her to be fully vaccinated for L4, she would need to come in AGAIN in another 4 weeks for an l4 booster. I chose not to, as i am happy enough for her to be protected up to L2 and didnt want to risk over vaccination.
Since then, every year for her lepto booster, she has received the L4, but is this pointless, and she might as well just have L2 annually (as this is all she is protected up to anyway)? Or is there, even without the second interval of injections for l4, ‘some’ immunity for the extra 2 strains, so beneficial to receive l4 annually, despite not being boosted first time round?
I have since read that L2 and L4 are not compatible, and the initial first course should have still been two injections using the SAME vaccine, and you can’t ‘mix and match’. Is this true?
*UPDATE* I have just since seen that MSD are discontinuing their supply of Nobivac® Lepto 2, and current batches will expire mid 2025 anyway. I assume this will mean every dog owner currently receiving the annual l2 booster, will need to change to l4 and receive another l4 4 weeks later if they wish to fully protect up to the 4 strains of lepto? Or can they just receive an l4 booster, without the second booster 4 weeks later, meaning their dog is technically still only fully protected up to 2 strains (l2)? Which is kind of like the situation my dog is currently in.
So, if you boost L2 with L4, but do not give the 4 week second vaccine, coverage against the Leptospira serogroups icterohaemorrhagiae and L. canicola strains may not be licensed, but it is highly likely that it will effectively boost immunity, as the exact same strain of Canicola is used, and a closely related strain of Icterohaemorrhagiae – and because they are both serovar Copenhageni, we would expect them to be cross-reactive. Anyone who wants to get coverage for the other two, though, definitely needs the second dose to generate an anamnestic response. I doubt people will be forced to change, but it’s worth considering the insurance situation, as insurance companies may not cover if “incompletely” vaccinated, and the second 4 dose would also generate licensed immunity against the other two strains.
Hope that helps!
Right now, my pet Golden Retriever is taking the antibiotic medicine, which will be completed on 6th of February 2025, and his scheduled vaccination dates are
laplopirosis on 13th January, Rabies 4th Feb, and Corona 25th Feb. Will we delay the vaccination schedule? or keep the same date?
You would need to confirm with the prescribing vet, as although antibiotics are unlikely to affect those vaccines, any underlying i nflection or inflammatory process will reduce the effectiveness of the vaccine.
My dog has only had one needle when he was a baby he’s now nearly 2 would he have to start the course of needles all over again thanks
Yes, but it’s not so complicated as an adult. He would probably only need a single injection of the distemper, hepatitis and parvo component to generate immunity, although he would need a second dose of the lepto component (a core vaccine in the UK).
My dogs second vaccination date has lapsed by 2 weeks. Do I have to repeat the course? I’m due to go on holiday on the 2nd of June and the kennels need both jabs done.
It depends which vaccine she had. For the Distemper, Parvo and Hepatitis components – no, a single injection is enough to generate strong immunity IF given after their mother’s immunity has worn off (which is why we use a 2-dose primary course).
However, if the vaccine protocol contains other vaccines, such as leptospirosis, then those may need to be restarted as other vaccines require 2 doses at an exact interval to give the best protection.
What if my puppies got only 2 vaccine an now thy already 4months .
It depends which vaccine it is! Most vaccines in dogs only need 2 doses for initial protection, plus a booster at 12 months, and then every 3 or year, depending on the disease.